Operating parameters of electrical equipment must often be measured or determined for a variety of reasons. For example, a complex electrical circuit within an aircraft or in a component used in an aircraft requires thorough electrical testing to verify its usefulness and reliability. Similarly, complex electrical circuitry present in other working environments also requires thorough testing to determine its reliability.
Typically, the manner in which complex electrical circuitry has heretofore been tested involved hard wiring (i.e., permanent attachment) of incoming signal lines from the devices under test to a test fixture. The test fixture normally utilized a pin and a cantilever spring concept. Undesired bending of the contacts in the test fixture made it difficult for the user to re-align the contacts for proper use. Another disadvantage of such manner of testing is that the fixture assembly is hard-wired and therefore dedicated to a particular test requirement. This type of test system was not only expensive but also inherently limiting in its adaptability.